The present invention relates to a new and improved construction of apparatus for applying solder to the connections of integrated circuit components, and more specifically serves to apply solder located in a solder bath to the connections or terminals of integrated circuit components in a dual-in-line housing (DIL-housing).
Integrated circuit components in a DIL-housing, i.e. component units constructed in integrated circuit technology, are used increasingly in electronic installations since they exhibit a great packing density of the components, and thus, there is possible a low volume and low weight. Another advantage is the drastic reduction in the number of solder connections when forming extensive assemblies, which, not least of all, beneficially affects the mean faultless operating time of an installation in a favourable manner. However, increasingly greater requirements are placed upon the solder locations. Frequently the connections of commercially available IC-components do not satisfy these requirements as concerns their solderability, and therefore it is frequently necessary, following the solder operation, to undertake complicated testing and post-soldering work in order to ensure for a faultless quality of the solder locations, and thus, the disturbance free functionality of the equipment which is composed of such components.
These drawbacks can be countered in that prior to the actual soldering operation performed at the component groups or assemblies the terminals or connections of the IC-components are pre-tin plated, i.e. initially tin plated. In so doing there however exists the problem of completely and uniformly imbuing with solder each connection or terminal, in particular tin plating the connection up to a location close to its bending location or point. With vertical immersion of the connections in a solder bath their maximum immersion depth however is essentially governed by the spacing of the base or bottom surface of the component from the free ends of the connections. Furthermore, there must be taken into account that in the immersed condition there must be maintained a safety distance or spacing between the component and the upper surface of the solder bath, in order to protect the component against impermissible heating, which in turn, limits the maximum immersion depth of the connections.